Ethmoid Labyrinth, Lateral View

Description

Ethmoid labyrinth (lateral mass) fills the central portion of this lateral skull-base view, with the lamina papyracea forming a broad, smooth lateral plate that constitutes much of the medial orbital wall. Medial to this thin orbital lamina, the honeycomb ethmoidal air cells occupy the body of the labyrinth, while the uncinate process projects inferiorly as a curved lamella along the lateral nasal wall. The perpendicular plate is included as a midline extension, seen posterior to the nasal bones and continuous superiorly toward the cribriform region, anchoring the relationship between the ethmoid and the nasal septum. Endoscopic sinus surgeons care about this anatomy because millimeters matter at the orbit. Violation of the lamina papyracea during functional endoscopic sinus surgery can lead to orbital fat prolapse or extraocular muscle injury, and the illustration’s fixed lateral perspective makes the paper-thin orbital wall easy to appreciate against the more complex ethmoidal masses. The uncinate process, as a key boundary of the ethmoidal infundibulum and ostiomeatal complex, also frames how obstruction can contribute to anterior ethmoid and maxillary sinus drainage disease. Thin bone. High stakes. Use this illustration in head and neck anatomy teaching to orient learners to the ethmoid’s lateral masses before introducing coronal CT of the paranasal sinuses, or in an otolaryngology operative atlas to label the lamina papyracea and uncinate process as surgical landmarks for safe dissection. It also suits ophthalmology and trauma publications discussing medial orbital wall fractures and secondary orbital complications of ethmoiditis. Anatomical accuracy verified by SciePro's Medical Advisory Board.